Flotation device equipped with a road-section for the construction of floating bridges or motor-ferries

ABSTRACT

A float, preferably an amphibious vehicle for use in erecting pontoon bridges or powered rafts, is provided with a road section having rigid extensions pivotally connected to the longitudinal sides thereof for downward movement about axes parallel to the longitudinal axis of the road section with coupling means at its ends and being pivotable by power means about an axis perpendicular to the road section of the vehicle.

United States Patent Behrmann et al.

[54] F LOTATION DEVICE EQUIPPED WITH A ROAD-SECTION FOR THE CONSTRUCTION OF FLOATING BRIDGES OR MOTOR-FERRIES [72] Inventors: Georg Behrmann, Lauf A. D. Pergnitz;

Rudolf Schubart, Nurnberg, both of Germany [73] Assignee: DipL-Ing. Karl Heinz Schmidt, Kreis Hersbruck, Germany [22] Filed: Oct. 22, 1969 [21] Appl. No.: 868,360

[30] Foreign Application Priority Data Oct. 22, 1969 Germany ..P 18 04 498.9

[52] U.S. Cl ..14/1, 14/27 [51] Int. Cl ..E0ld 1/00 [58] Field of Search ..14/1, 27

[451 Mar. 28, 1972 [56] References Cited UNITED STATES PATENTS 2,321,677 6/1943 Higgins ..14/27 UX 2,341,166 2/1944 Todd ....14/27 X 2,636,197 4/1953 Odot ....14/27 2,944,270 7/1960 Pearse 14/27 3,021,544 2/ 1962 Gillois.... 14/27 3,152,569 10/1964 Gehlen ..14/27 X Primary Examiner-Jacob L. Nackenofi Attorney-l-lolman, Glascock, Downing and Seebold 57 ABSTRACT A float, preferably an amphibious vehicle for use in erecting pontoon bridges or powered rafts, is provided with a road section having rigid extensions pivotally connected to the longitudinal sides thereof for downward movement about axes parallel to the longitudinal axis of the road section with coupling means at its ends and being pivotable by power means about an axis perpendicular to the road section of the vehicle.

14 Claims, 10 Drawing Figures P'A'TE'NSTED M28 1972 SHEET 1 OF 7 PATENTEB MR 2 8 I972 SHEET 2 [IF 7 FIG.3

FIG. 2

PATENTEDMAM m2 3' s51 52s SHEET 3 OF 7 FIGJ P'ATENTEDMAm m2 3, 651 ,528

SHEET 5 0F 7' I UFW UM J! U l i WW! .f g N v f v v K 2. m no 9. m Q9 Q9. m? o- F LOTATION DEVICE EQUIPPED WITH A ROAD- SECTION FOR THE CONSTRUCTION OF FLOATING BRIDGES OR MOTOR-FERRIES BACKGROUND OF THE INVENTION This invention relates to a float, and more particularly an amphibious vehicle for use in erecting pontoon bridges, motor ferries, powered rafts and the like.

Such floats are described, for example, in 'the printed publication Brochure Of The Mobile Floating Assault Bridge Ferry" issued by the United States Army Research and Development Laboratories, Fort Belvoir, Virginia on Dec. 1, 1964. In these known floats, a stub keyed shaft which is rotatable via power means is arranged in the center of the deck of an amphibious vehicle and on which can be selectively mounted either a ramp member having a ramp portion capable of being raised about a horizontal transverse axis by powermeans or a road section, both of which along the longitudinal sides of the road section provided with the coupling means at the ends have the rigid extension capable of being turned downwardly by power means about axes parallel to the longitudinal axis of the road section. Also, insertable vertical pins are arranged on the deck of the vehicle and these pins permit the applied ramp member or road section as the case may be to befixed either in the longitudinaldirection or the transverse direction of the vehicle.

The rigid extensions pivotally connected to the sides of the ramp or road section are narrow and' when in the horizontal position do not appreciably widen -the road section although relatively powerful pressure medium drives specifically'provided for the purpose are necessary for moving such rigid extensions.

The width of the amphibious vehicle and the width of each of the ramp or road sections which can be mounted thereon is limited to a maximum value by the prevailing traffic regulations. On the other hand, pontoon bridges erected of such floats should have a road width which, as far as possible, allow the passing of vehicles of the same width or of greater width than that of the amphibious vehicles per se or even the simultaneous passing of two columns of vehicles next to one another with the columns being constituted of vehicles of smaller or equal width.

The above problem is discussed in German Pat. No.

1,035,679 which discloses a float constituted as an-amphibious vehicle and on the deck of which are arranged two road sections. The two road sections are rotatable about vertical axes which are off center and the width of which corresponds to substantially half the width of the vehicle. The road sections when located in the longitudinal direction ofthe vehicle have their facing longitudinal edges in direct abutment with one another while upon rotation in the transverse direction of the vehicle, the sections are retracted from one another due to the eccentricity of the two pivotal axes so that they can accommodate therebetween a third road section which in the transporting position rests on the two above-mentioned road sections in the longitudinal direction.

It is possible, in this manner, to erect pontoon bridges of appreciably greater road width. This solution, however, in itself quite advantageous, requires a substantial expenditure on technical material for its practical execution. In particular, the interposition of the third road section requires very powerful pressure actuated lifting devices of complex structure and even so can hardly be effected without additional manual assistance and a corresponding expenditure of time. These technical difficulties are even greater in the situation of floats in which the road sections are equipped with associated ramp members.

The object of the present invention is to solve the problem of enabling the extensions of floats of the general type above described to be made wider without the employment of special pressure medium drives forbringing such extensions into position for allowing the rapid construction of pontoon bridges, powered rafts or the like having a substantially great road width in the shortest possible time and with a minimum amount of manual labor, by using floats of relatively simple structural detail.

SUMMARY OF THE INVENTION In accordance with the invention, the problem is solved by providing a float of the above-described type in which the pivotal axes of the rigid extensions which are at least approximately one-half the width of the road section are so arranged relative to the pivotal axis of the road section and the two upper longitudinal edges of the amphibious vehicle and which edges are rounded and/or provided with sliding means so that with the road section located in the longitudinal direction of the amphibious vehicle, the two rigid extensions hang downwardly along the two longitudinal sides of the vehicle and substantially cover such sides and, upon turning the road section into a position transverse to the longitudinal axis of the amphibious vehicle, the rigid extensions are displaced upwardly into their horizontal positions by the sliding of the undersurfaces of such extensions over the upper longitudinal edges of the vehicle.

The present floats, compared with the known floats, represent a very considerable technical advance since the rigid extensions pivotally connected to the two longitudinal sides of the road section may be of very appreciable width and no special pressure medium drives are necessary for moving such rigid extensions from their downwardly hung position into their horizontal position or vice versa, since the motive forces required for such ends represent but a small portion of the great rotary drive forces necessary for turning the road section about its vertical axis of rotation and the static and possibly the dynamic forces of buoyancy can be utilized to a great degree when driving the amphibious vehicle into the water to be bridged'or traversed, or the force of gravity when leaving the water.

Moreover, in accordance with the present invention, there are preferably provided on the road section or on the two rigid extensions, releasable latches which hold the two rigid extensions in their upturned or horizontal position and with the latches engaged, the road section together with the two rigid extensions constitutes a unitary, rigid platform which is capable of pivotal movement about a vertical pivotal axis relative to the amphibious vehicle and which can assume any desired angular position relative to the vehicle. By virtue thereof, not only is the maneuverability of powered rafts considerably better than that of the rafts erected from known floats, but there is also the possibility, in the situation of pontoon bridges, of floats arranged over flowing water, of so placing the individual vehicles in the water independently of the direction of the bridge as an entity that such vehicles offer their lowest flow resistance and as a consequence subject the associated pontoons to the smallest action of the flowing water.

In a preferred practical embodiment of the invention, the road section is secured to a rotary member pivotally connectedto the amphibious vehicle, preferably by a ring of ball bearings, with such rotary member being buoyant and defined by a pontoon which is preferably closed with the width thereof being substantially equal to the width of the amphibious vehicle, and the longitudinal sides thereof being substantially vertical walls parallel to one another and the two end walls being defined by substantially vertical walls curved into arcs concentric with the axis of rotation and the height thereof being such that the road section when located in the longitudinal direction of the vehicle substantially fills a recess provided in the top of the vehicle and matches its periphery and extends over the whole width of the vehicle and holds the road section directly over fore and aft deck portions which are in alignment with one another and separated by the recess.

This particular float construction is advantageous in that a very stable connection is ensured between the road section being necessary for turning such components, as well as largely avoiding the occurrence of undesirable torque on the components transmitting the turning movement.

In accordance with a further aspect of the present invention, the road section is preferably mounted in horizontal guides in the rotary member and is movable by power means, with the horizontal guides being preferably arranged on the rotary member at such a level that the road section can be shifted relative to the amphibious vehicle, even when extending in the longitudinal direction of the vehicle.

The present float is further efficacious in that both in the erection of powered rafts and in the erection of pontoon bridges, the amphibious vehicles can be turned not only in any desirable angular position, relative to the associated power raft or associated bridge roadway, but can also travel laterally to a limited extent which is advantageous, for example, when precise trimming is required, in the case of powered rafts or a particularly good approach is necessary in the roadway in the vicinity of the bank in the case of bridges.

In all of the various constructional embodiments of the present invention, the road section and the rigid extensions pivotally connected to the two longitudinal sides of the road section may be constituted either as mere road sections or as ramp sections, or as ramp portions pivotal about horizontal transverse axes may be pivotably connected to the sides of components which per se are defined as mere road sections.

In accordance with a further aspect of the invention, the road section is subdivided into two components located one behind the other in the longitudinal direction and pivotably connected together by pivot means having a pivotal axis paral lel to the road section with the components being capable of being inclined, preferably by power means, to one another at an angle up to 40.

With the float constructions of the present invention, it is possible to make use of only one single type of float in the erection of pontoon bridges and the formation of powered rafts since special ramp units are no longer necessary, thereby appreciably reducing the technical apparatus which must be maintained available, as well as the time necessary for building a bridge or raft as no preforming of the vehicles to be employed is required.

Further objects and advantages of the present invention will become more readily apparent to persons skilled in the art from the following detailed specification and annexed drawings and in which drawings:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagrammatic side view of a float in accordance with the invention for forming pontoon bridges or powered rafts in which the float is constituted by an amphibious vehicle;

FIG. 2 is a diagrammatic rear elevational view of the float shown in FIG. 1 with a road section located in the longitudinal direction of the amphibious vehicle and a rigid extension located in the horizontal position;

FIG. 3 is a view taken along the Line IIl-III of FIG. 1, with the road section located in the longitudinal direction of the vehicle and the rigid extensions being shown in the horizontal position in full lines and in the downturned position in the dotdash lines.

FIG. 4 is a diagrammatic plan view of the float illustrated in FIGS. 1-3, with the road section being illustrated in the longitudinal direction of the vehicle and the rigid extensions in the horizontal positions;

FIG. 5 is a diagrammatic side view of a powered raft formed from two floats in accordance with the showings in FIGS. L4;

FIG. 6 is a view generally similar to FIG. 5 but illustrating a still further operating condition;

FIG. 7 is a diagrammatic side view of a powered raft formed from three floats;

FIG. 8 is a diagrammatic side view of part of a bridge over a body of water employing the powered raft illustrated in FIG. 7, and incorporating a further float;

FIG. 9 is a diagrammatic partial plan view of a completed pontoon bridge erected of floats according to the invention; and

FIG. 10 is a diagrammatic side view of a modified embodiment of a powered raft formed with the employment of the present float.

DETAILED DESCRIPTION OF THE INVENTION As illustrated diagrammatically in FIGS. 1-4, the preferred embodiment of the float according to the present invention for forming pontoon bridges for powered rafts comprises a transport vehicle in the form of an amphibious vehicle. The wheels of the vehicle are of known retractable type and when retracted nest in wheel wells into which gas under pressure may be introduced so that during travel of the vehicle on water, the flow resistance is reduced and the buoyancy of the vehicle increased. The amphibious vehicle is shown, by way of example, as a twin screw vehicle so that during travel through water, the vehicle can be steered by means of propellers which are preferably reversible, thereby eliminating the use of separate steering means. In a modification thereof, the vehicle, may, of course, be provided with different steering means for water travel.

It will be noted that the transport vehicle denoted generally 1 is provided in its upper portion thereof with a recess 2 which extends transversely across the vehicle body thereby providing fore and aft raised parts 3 and 4 whose upper ends are closed by decks preferably in the same plane. The base of the recess 2 provides an intermediate deck on which a ring 5 of ball bearings is arranged. A rotary member 6 preferably in the form of a pontoon is carried by the ring 5. The member 6 is of a width substantially equal to the width of the vehicle. More specifically, the member 6 includes two substantially vertical parallel sidewalls and two substantially vertical arcuate end walls concentric with the axis of rotation of the ring 5, with the height of the member 6 being such that when the member is located in the longitudinal direction of the vehicle 1 it substantially fills the recess 2.

With reference to FIGS. 1 and 3, it will be noted that the rotary member 6 is provided with horizontal longitudinally extending guides 7 on which guide rollers 8 are mounted with such guide rollers engaging in corresponding guide grooves 9 provided in a road section denoted generally 10.

A toothed ring 1 1 is secured on the portion of the ring 5 adjacent the rotary member 6 and the pinion of a turning motor 12 engages the teeth of the ring 11. Two racks 13 which extend in the longitudinal direction are arranged on the undersurface or side of the road section 10 and engage pinions on two horizontal driving shafts journaled in the rotary member 6 and extending transversely thereof. The shafts are driven by drive motors 14. It will be appreciated therefore that by means of the drive motors 12 and 14, the member 6 can be rotated about a vertical axis concentric with the ring 5 and the road section 10 can be displaced along the horizontal guides 7 rela tive to the rotary member 6, respectively.

As best illustrated in FIG. 4, the road section 10 is subdivided into two portions 10a and 10b located one behind the other in the longitudinal direction of the vehicle and a transversely extending horizontal hinge 15 interconnects the portions 10a and 10b in such a fashion that such portions can be inclined to one another at an angle of up to approximately 40. Mutual inclination of the portions 10a and 10b may, for example, be effected via drives employing a pressure medium. However, the hinge 15 is preferably defined by a known socalled steep pitch pressure medium actuated hinge. It is to be understood that the mutual inclination of the portions 10a and 10b is only possible when the road section 10 as an entity has been displaced so far relative to the rotary member 6 along the longitudinal guides 7 that the transverse hinge has moved out of the zone of these guides.

A rigid extension denoted generally 17 is pivotally connected to each outer longitudinal edge of the road section 10 about a horizontal longitudinally extending hinge means 16. In

FIGS. 14, the extensions 17 are shown in the horizontal position in full lines and in the vertical or downwardly hung position by dot-dash lines in FIG. 3.

The road section together with the extensions 17 are preferably buoyant and the extensions 17 are subdivided into portions 170 and 1711 located onebehind the other in the longitudinal direction. The extension 17 may, for example, be approximately one-half the width of the road section 10, and in practice, the width of the extensions 17 are subject only to the limit imposed by the minimum permissible ground clearance of the amphibious vehicle when the extensions are in the downwardly hung position as illustrated by the dot-dash lines in FIG. 3.

The axes of the hinge means 16 between the road section 10 and the extensions 17 are so arranged relative to the two upper longitudinal edges of the amphibious vehicle 1 that with the road section 10 located in the longitudinal direction of the vehicle, the extensions 17 hang downwardly along the longitudinal sides of the vehicle and substantially cover such sides. However, upon rotation of the rotary member 6 and as a consequence the road section 10 transversely to the longitudinal axis of the vehicle 1, the undersurfaces of the extensions 17 slide along the upper longitudinal edges of the vehicle 1 for turning the extensions 17 into their horizontal position. As illustrated in FIGS. 2 and 3, the lower and inner sides of the extensions l7 are complementary to the two sides of the amphibious vehicle 1 thereby providing a suitable cross section for the extensions 17 and an excellent utilization of the space within the sectional gauge of the vehicle profile when the extensions are in their vertical position, respectively. It will further be seen from these same figures that the axis of each hinge means 16 is arranged on the two lower longitudinal outer edges of the road section 10 and on the inner longitudinal edges of the extensions 17 which edges, of course, are the lower edges when the extensions 17 are in the horizontal position.

Hence, with the extensions 17 in the horizontal position, there is provided, due to the mutual abutment of the adjoining longitudinal edges of the road section 10 on the one hand and the extensions 17 on the other hand, a construction which will withstand upwardly directed bending forces and provides in effect a rigid flat road surface having a width which is at least twice the width of the vehicle 1. As shown in FIGS. 2 and 4, latches 18 are arranged on the road section 10 which, when the extensions are in the horizontal position automatically engage in corresponding noses on the extensions for holding the extensions fastly in the horizontal position. The latches 18 may be released either manually or by the action of a pressure medium.

For facilitating the upward movement of the extensions 17 upon the rotation of the road section 10 into the transverse direction relative to the amphibious vehicle 1, it will be noted that the two upper longitudinal edges of the vehicle 1 are rounded as shown at 19 (FIG. 2) and rolling members such as, for example, balls 20 are provided on the lower or inner side of the extensions 17 in the zone of the rounded edges 19.

For the upward movement of the extensions 17 upon rotation of the road section 10 transversely of the longitudinal axis of the vehicle 1, it is necessary for the length of the extension 17, possibly subdivided into the portion 17a and 17b, to be so great that such components engage over the fore raised part 3 and the aft raised part 4 of the amphibious vehicle. In order to ensure that the extensions 17 will remain as required in their downturned vertical positions particularly when the. vehicle is travelling along roads or during special maneuvers when operating on water, the sidewalls of the rotary member 6 are provided with electromagnets 21 (FIGS. 1 and 3) which maintain the extensions 17 against the sidewalls of the member 6. When it is desired to move the extensions 17 into the horizontal position, it is merely necessary to deenergize the electromagnets 21 and it is, of course, to be understood that latches or other holding means may be employed in lieu of the electromagnets.

The height of the rotary member 6 is preferably such and the horizontal guides 7 are arranged at such a level that the road section 10 can also be shifted as regards its longitudinal position relative to the amphibious vehicle I as illustrated in FIG. 1.

As illustrated in FIGS. 1 and 4, the vehicle 1 is provided with a drivers cab or compartment 22 and a control turret 23 can be lowered into the fore raised part 3 of the vehicle or elevated therefrom. It will be seen that the turret 23 is located in the zone of rotation of the road section 10 and the turret can serve as a control point particularly when the float is travelling on the water and within which all of the actuating components for maneuvering the float are arranged.

The operation of the preferred embodiment of the invention as illustrated in FIGS. 1-4 is as follows and attention is directed to FIGS. 5-9:

Assuming that a pontoon bridge is to be erected over flowing water, two or more of the vehicles are driven into the water at a suitable location along the bank. The driving of the vehicles into the water is facilitated by the wheels being suspended on retractable members (FIG. 1) which not only enable the wheels to be retracted into the wheel wells acted upon by air for water travel but additionally permit adjustment of any desired ground clearances for the vehicle being driven into the water in the region of the bank. As soon as the vehicle 1 is in the water, the wheels are retracted and the vehicle is converted from land travel to water travel. The electromagnets 21 are then deenergized with the result that the extensions 17 which are buoyant will move upwardly to a considerable extent due to their buoyancy from the vertical positions assumed by the extensions during the land travel of the vehicle 1.

The rotary member 6 is then rotated by the drive motor 12 into the transverse direction relative to the vehicle 1 so that the portions 17a and 17b of the extensions 17 which are diagonally opposite (FIG. 4) are moved upwardly by the sliding of their inner sides provided with the balls 20 on the rounded upper longitudinal edges 19 of the raised fore and aft parts 3 and 4 until the latches l8 engage for maintaining such portions in the horizontal position. Thereafter, by rotation of the rotary member 6 in the opposite direction, the other two portions 17a and 17b which are diagonally opposite are moved upwardly into their horizontal positions. The road section 10 together with the horizontal rigid extensions 17 now constitutes a rigid road platform which is adjustable to any desired angle relative to the amphibious vehicle 1.

The road platform is then preferably adjusted to approximately the transverse position relative to the amphibious vehicle 1, whereupon the control turret 23 can be raised above the deck of the fore part 3. In this condition, the unit is highly maneuverable substantially like a ship and inasmuch as both the road section 10 and the extensions 17 and the rotary member 6 are formed as buoyant components, the vehicle has a greater buoyancy the lower the vehicle becomes in the water due to increasing traffic load. This, of course, is conditional upon the road section 10 not being able to lift from the rotary member 6 or the rotary member 6 being able to lift from the ring 5.

When at least two floats A and B are in this operating condition in the water, the ends of the road sections or rigid extensions can be brought together and coupled to provide a powered raft as illustrated in FIG. 5. For this purpose, the ends of the road section 10 and the extensions 17 are provided with automatic coupling means and numerous forms of such means are known in the art and constitute no part of the present invention.

The raft illustrated in FIG. 5 is constituted, by way of example, of two vehicles A and B and is particularly maneuverable since both in the case of the vehicle A and also vehicle B, rotation of the rotary member 6 together with the road section 10 and the associated extensions 17 relative to the vehicle 1 is possible. As a consequence, these vehicles per se function, so to speak, as a screw driven control component in relation to the rigid platform defined by the two road sections 10 and associated rigid extensions 17.

It should be mentioned that in FIGS. -9 the approximate depth of immersion of the vehicles under traffic load is indicated in dot-dash lines.

The next maneuver to be executed by the powered assemblage constituted by the vehicles A and B is that by actuation of the drive motors 14, the road sections can be shifted longitudinally relative to the rotary member 6 so that the vehicles 1 which are transverse thereto come into contact as illustrated in FIG. 6 and thus the respective transverse hinges leave the guides 7 on both sides in order that an unhindered inclination of the portions 10a and 1012 on both sides is possible. The assemblage defined by the vehicles A and B is now in the operating condition in which the road portions 10b and their associated extension portions 17b are coupled to one another at their ends and hence the members 6 also abut end to end and the two vehicles 1 have approached one another. The road portions 10a with their associated extension portions 17a which now project freely outwardly beyond the rotary member 6 on both sides can be inclined upwardly and downwardly, as desired, about the transverse hinges 15 as illustrated in FIG. 6. The powered raft which is highly maneuverable is therefore in an operating condition which enables the raft to perform substantially all of the work required in the vicinity of the bank or in the middle of the water body for further development of the bridge or other work which may be necessary.

In the further description of the operation, and for the sake of simplicity, reference will be made only to the road section 10 and road portions 10a and 10b of the vehicle concerned, it being understood that the maneuvers performed by these components are automatically performed at the same time by the extension portions 17a and 17b respectively associated therewith.

As illustrated in FIG. 7 the raft, may, if necessary, be widened by the addition of a third vehicle C. Inasmuch as the vehicles are of identical construction, the road portion 10a of the vehicle B, for example, can at once be coupled to the road portion 10b of the vehicle C and then, by actuation of the drive motor 14 of the vehicle C, the rotary member 6 of the vehicle C can be shifted to the left in the longitudinal direction relative to the road section 10 of this vehicle so that its longitudinal guides 7 enter the guide grooves of the road portion 10a of the vehicle B. As a consequence not only does the road portion 10a of the float C project to the right beyond its rotary member, but its road portion 10b also projects to the right beyond the rotary member 6 of the vehicle by an appreciable part ofits length.

FIG. 8 illustrates this assembly, increased by a further vehicle D driven to the vicinity of a bank so that a bridge head is now provided.

In accordance with a further aspect of the invention, there may be arranged both on the outer or lower longitudinal edges of the rigid extension 17 and also on the two longitudinal edges of the road section 10 coupling means which may be known per se and which can be caused to coact with the coupling means on the ends of these components of other vehicles during the assemblage of powered rafts or pontoon bridges. The coupling means arranged on the longitudinal sides of the road section, must, of course, be so arranged or constructed that such coupling means do not interfere with the raising of the rigid extensions 17.

The provision of such additional coupling means makes it possible to incorporate vehicles in a powered raft, for example, with the road section 10 located in the longitudinal direction of the vehicle with its rigid extensions not raised or in the manner illustrated in FIG. 10 with an extension or extensions raised only on one side or with the extension raised on both sides. This provides yet a further ability for complying with different prescribed lengths or widths in the building of powered rafts or pontoon bridges.

The invention is not to be limited to the preferred embodiment above described and, for example, a simplified practical embodiment is possible in which the road section 10 and the extension 17 pivotally connected to both sides thereof are not subdivided into road portions 10a, 10b or extension portions 17a, 17b which are one behind the other in the longitudinal direction. The transverse hinge 15 is omitted in this situation and such a simplified embodiment has only the disadvantage, which is not decisive in all applications, that either additional ramp parts are necessary or that vehicles with road sections formed solely as road portions and vehicles with road sections formed as ramp sections respectively must be maintained available. In yet a further simplification of the vehicle structure, the ability of the road section 10 to be capable of longitudinal displacement relative to the rotary member 6 may be omitted and even such a simplified embodiment of the invention is advantageous for many uses.

Finally, it is not absolutely essential for the rotary member to be formed in the manner of a pontoon. Instead, it may, for example, be a rotary disc having a circular periphery which is preferably a buoyant member and the diameter thereof corresponding to the width of the vehicle. Such an embodiment is also advantageous for many uses.

In all of the simplified embodiments of the invention, the main advantage of the preferred embodiment is still realized in that no separate drive is required for raising and lowering the rigid extensions on both sides, with the forces of buoyancy upon entry of the vehicle into the water or the force of gravity upon emerging from the water being utilized.

I claim:

1. A float, preferably an amphibious vehicle for use in building pontoon bridges, powered rafts and the like capable of being dismantled, comprising a body, a road section for the body, means mounting the road section on the body for rotary movement about a vertical axis relative to the body, a rigid extension for each longitudinal edge of the road section, said road section having coupling means at the ends thereof, means hingedly mounting each rigid extension to the road section for downward movement about an axis parallel to the longitudinal axis of the road section, the width of each rigid extension being at least half the width of the road section, and the upper longitudinal edges of the body and the lower surface of the rigid extensions coacting with each other in a manner that, when the road section extends along the longitudinal direction of the body, the rigid extensions hang downwardly along the longitudinal sides of the body and substantially cover the such sides, while rotation of the road section relative to the body into a position transverse to the longitudinal axis of the body causes the lower surfaces of the rigid extensions to slide around the upper longitudinal edges of the body and thus to swing the extensions upwardly into horizontal positions in substantial alignment with the surface of the road section.

2. The float as claimed in claim 1 in which releasable latches retain the rigid extensions in their horizontal position.

3. The float as claimed in claim 1 in which releasable holding means retain said rigid extensions in their downwardly hanging position when the road section is located in the longitudinal direction of the body.

4. The float as claimed in claim 1 in which said pivotal mounting means are located on the two lower longitudinal edges of the road section and the inner lower longitudinal edges of the rigid extensions and extend in a horizontal direction.

5. The float as claimed in claim 1 including rollers for facilitating the sliding of the rigid extensions.

6. The float as claimed in claim 1 in which each rigid extension includes a plurality of sections located one behind the other in the longitudinal direction.

7. The float as claimed in claim 1 in which said rigid extensions are buoyant.

8. The float as claimed in claim 1 in which the means mounting the road section for rotary movement relative to the body include a rotary member to which the road section is connected and a rotatable ring on the body to which the rotary member is connected.

9. The float as claimed in claim 8 in which said rotary member includes a pontoonhaving a width substantially equal to the width of the vehicle and longitudinal sides defined by substantially vertical parallel walls and end walls formed by substantially vertical walls having an arc concentric to the axis of rotation, the height of the pontoon being such that when the road section is located in the longitudinal direction of the body, the pontoon approximately fills a recess provided in the upper side of the body with the recess corresponding in shape and extending over the entire width of the body and holding the road section directly above front and rear raised portions aligned with and separated from each other by the recess.

10. The float as claimed in claim 9 in which the rotary member is provided with horizontal guides for supporting the road section.

11. The float as claimed in claim 10 in which the horizontal guides are located on the rotary member at such a height that the road section can be displaced relative to the body even when the road section extends in the longitudinal direction of the body.

12. The float as claimed in claim 6 in which said road section includes at least two parts arranged one behind the other in the longitudinal direction, means pivotally connecting said parts along an axis extending transverse to the road section and said parts being tiltable relative to each other through an angle of up to approximately 40.

13. The float as claimed in claim 1 including a control turret mounted in the body in the area of rotary movement of the road section on the upper side of the body, and means for raising and lowering the turret relative to the body,

14. A float, preferably an amphibious vehicle for use in building pontoon bridges, powered rafts and the like which are capable of being dismantled, comprising a body, said body, in-

termediate the ends thereof, having a recess extending transversely thereof providing an intermediate deck portion and axially spaced fore and aft deck portions, a road section, means mounting the road section for rotation about a vertical axis on said intermediate deck portion, said road section mounting means having a width substantially equal to the width of the body and the height of said mounting means being such that when said mounting means is located in the longitudinal direction of the vehicle, said mounting means substantially fills the recess, the length of said road section being such that with the mounting means located in the longitudinal direction of the vehicle, the road section is held directly above the fore and aft deck portions, complemental guide means on said mounting means and road section cooperable to permit relative longitudinal movement between the mounting means and the road section, a rigid extension for each longitudinal edge of the road section, means hingedly mounting each rigid extension to each longitudinal edge of the road section for downward movement about an axis parallel to the longitudinal axis of the road section, the width of each rigid extension being at least half the width of the road section, and the upper longitudinal edges of the body and the lower surface of the rigid extensions coacting with each other in a manner that, when the mounting means and the road section extend along the longitudinal direction of the body, the rigid extensions hang downwardly along the longitudinal sides of the body and approximately cover the longitudinal sides, while rotation of the mounting means and the road section relative to the body into a position transverse to the longitudinal axis of the body causes the lower surfaces of the rigid extensions to slide around the upper longitudinal edges of the body and thereby swing the rigid extensions upwardly about their hinged mountings in horizontal positions in substantial alignment with the road section. 

1. A float, preferably an amphibious vehicle foR use in building pontoon bridges, powered rafts and the like capable of being dismantled, comprising a body, a road section for the body, means mounting the road section on the body for rotary movement about a vertical axis relative to the body, a rigid extension for each longitudinal edge of the road section, said road section having coupling means at the ends thereof, means hingedly mounting each rigid extension to the road section for downward movement about an axis parallel to the longitudinal axis of the road section, the width of each rigid extension being at least half the width of the road section, and the upper longitudinal edges of the body and the lower surface of the rigid extensions coacting with each other in a manner that, when the road section extends along the longitudinal direction of the body, the rigid extensions hang downwardly along the longitudinal sides of the body and substantially cover the such sides, while rotation of the road section relative to the body into a position transverse to the longitudinal axis of the body causes the lower surfaces of the rigid extensions to slide around the upper longitudinal edges of the body and thus to swing the extensions upwardly into horizontal positions in substantial alignment with the surface of the road section.
 2. The float as claimed in claim 1 in which releasable latches retain the rigid extensions in their horizontal position.
 3. The float as claimed in claim 1 in which releasable holding means retain said rigid extensions in their downwardly hanging position when the road section is located in the longitudinal direction of the body.
 4. The float as claimed in claim 1 in which said pivotal mounting means are located on the two lower longitudinal edges of the road section and the inner lower longitudinal edges of the rigid extensions and extend in a horizontal direction.
 5. The float as claimed in claim 1 including rollers for facilitating the sliding of the rigid extensions.
 6. The float as claimed in claim 1 in which each rigid extension includes a plurality of sections located one behind the other in the longitudinal direction.
 7. The float as claimed in claim 1 in which said rigid extensions are buoyant.
 8. The float as claimed in claim 1 in which the means mounting the road section for rotary movement relative to the body include a rotary member to which the road section is connected and a rotatable ring on the body to which the rotary member is connected.
 9. The float as claimed in claim 8 in which said rotary member includes a pontoon having a width substantially equal to the width of the vehicle and longitudinal sides defined by substantially vertical parallel walls and end walls formed by substantially vertical walls having an arc concentric to the axis of rotation, the height of the pontoon being such that when the road section is located in the longitudinal direction of the body, the pontoon approximately fills a recess provided in the upper side of the body with the recess corresponding in shape and extending over the entire width of the body and holding the road section directly above front and rear raised portions aligned with and separated from each other by the recess.
 10. The float as claimed in claim 9 in which the rotary member is provided with horizontal guides for supporting the road section.
 11. The float as claimed in claim 10 in which the horizontal guides are located on the rotary member at such a height that the road section can be displaced relative to the body even when the road section extends in the longitudinal direction of the body.
 12. The float as claimed in claim 6 in which said road section includes at least two parts arranged one behind the other in the longitudinal direction, means pivotally connecting said parts along an axis extending transverse to the road section and said parts being tiltable relative to each other through an angle of up to approximately 40*.
 13. The float as claimed in claim 1 including a control turret mounted in the body in the area of rotary movement of the road section on the upper side of the body, and means for raising and lowering the turret relative to the body.
 14. A float, preferably an amphibious vehicle for use in building pontoon bridges, powered rafts and the like which are capable of being dismantled, comprising a body, said body, intermediate the ends thereof, having a recess extending transversely thereof providing an intermediate deck portion and axially spaced fore and aft deck portions, a road section, means mounting the road section for rotation about a vertical axis on said intermediate deck portion, said road section mounting means having a width substantially equal to the width of the body and the height of said mounting means being such that when said mounting means is located in the longitudinal direction of the vehicle, said mounting means substantially fills the recess, the length of said road section being such that with the mounting means located in the longitudinal direction of the vehicle, the road section is held directly above the fore and aft deck portions, complemental guide means on said mounting means and road section cooperable to permit relative longitudinal movement between the mounting means and the road section, a rigid extension for each longitudinal edge of the road section, means hingedly mounting each rigid extension to each longitudinal edge of the road section for downward movement about an axis parallel to the longitudinal axis of the road section, the width of each rigid extension being at least half the width of the road section, and the upper longitudinal edges of the body and the lower surface of the rigid extensions coacting with each other in a manner that, when the mounting means and the road section extend along the longitudinal direction of the body, the rigid extensions hang downwardly along the longitudinal sides of the body and approximately cover the longitudinal sides, while rotation of the mounting means and the road section relative to the body into a position transverse to the longitudinal axis of the body causes the lower surfaces of the rigid extensions to slide around the upper longitudinal edges of the body and thereby swing the rigid extensions upwardly about their hinged mountings in horizontal positions in substantial alignment with the road section. 